lib/AST/CMakeLists.txt: Update LLVM_USED_LIBS, not to miss symbols with building shared lib. Thanks to Ryuta Suzuki.
lib/AST/CMakeLists.txt: Update LLVM_USED_LIBS, not to miss symbols with building shared lib. Thanks to Ryuta Suzuki.

git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@135864 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,llvm-mirror/clang,apple/swift-clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang